Embodiments of the invention provide a magnetic disk drive whose flexibility in the layout of components is enhanced in spite of the fact that a magnetic disk and a driving section such as the voice coil motor that drives a head arm are isolated from each other. In one embodiment, a magnetic disk drive includes a magnetic disk compartment in which a magnetic disk, a head that reads/writes data from/onto the magnetic disk, and a head arm holding the head are disposed, and a VCM compartment with an internally disposed VCM that pivotally moves the head arm about a pivot shaft. The magnetic disk compartment and the VCM compartment are separated by an isolation wall provided at the bottom of the magnetic disk compartment along the recording surface of the magnetic disk. The pivot shaft is disposed in a penetrating form in an opening.